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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network200.80.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
200.80.0.0
Broadcast address
200.80.255.255
First usable
200.80.0.1
Last usable
200.80.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
C (default /24)
As numbers
Hex C8500000 · Integer 3360686080 to 3360751615
Reverse DNS zone
80.200.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001000.01010000..00000000.00000000200.80.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11001000.01010000..00000000.00000000200.80.0.0
Broadcast11001000.01010000..11111111.11111111200.80.255.255
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

200.80.0.0/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1200.80.0.0/28200.80.0.1 to 200.80.0.14200.80.0.1514
2200.80.0.16/28200.80.0.17 to 200.80.0.30200.80.0.3114
3200.80.0.32/28200.80.0.33 to 200.80.0.46200.80.0.4714
4200.80.0.48/28200.80.0.49 to 200.80.0.62200.80.0.6314
5200.80.0.64/28200.80.0.65 to 200.80.0.78200.80.0.7914
6200.80.0.80/28200.80.0.81 to 200.80.0.94200.80.0.9514
7200.80.0.96/28200.80.0.97 to 200.80.0.110200.80.0.11114
8200.80.0.112/28200.80.0.113 to 200.80.0.126200.80.0.12714
9200.80.0.128/28200.80.0.129 to 200.80.0.142200.80.0.14314
10200.80.0.144/28200.80.0.145 to 200.80.0.158200.80.0.15914
11200.80.0.160/28200.80.0.161 to 200.80.0.174200.80.0.17514
12200.80.0.176/28200.80.0.177 to 200.80.0.190200.80.0.19114
13200.80.0.192/28200.80.0.193 to 200.80.0.206200.80.0.20714
14200.80.0.208/28200.80.0.209 to 200.80.0.222200.80.0.22314
15200.80.0.224/28200.80.0.225 to 200.80.0.238200.80.0.23914
16200.80.0.240/28200.80.0.241 to 200.80.0.254200.80.0.25514
17200.80.1.0/28200.80.1.1 to 200.80.1.14200.80.1.1514
18200.80.1.16/28200.80.1.17 to 200.80.1.30200.80.1.3114
19200.80.1.32/28200.80.1.33 to 200.80.1.46200.80.1.4714
20200.80.1.48/28200.80.1.49 to 200.80.1.62200.80.1.6314
21200.80.1.64/28200.80.1.65 to 200.80.1.78200.80.1.7914
22200.80.1.80/28200.80.1.81 to 200.80.1.94200.80.1.9514
23200.80.1.96/28200.80.1.97 to 200.80.1.110200.80.1.11114
24200.80.1.112/28200.80.1.113 to 200.80.1.126200.80.1.12714
25200.80.1.128/28200.80.1.129 to 200.80.1.142200.80.1.14314
26200.80.1.144/28200.80.1.145 to 200.80.1.158200.80.1.15914
27200.80.1.160/28200.80.1.161 to 200.80.1.174200.80.1.17514
28200.80.1.176/28200.80.1.177 to 200.80.1.190200.80.1.19114
29200.80.1.192/28200.80.1.193 to 200.80.1.206200.80.1.20714
30200.80.1.208/28200.80.1.209 to 200.80.1.222200.80.1.22314
31200.80.1.224/28200.80.1.225 to 200.80.1.238200.80.1.23914
32200.80.1.240/28200.80.1.241 to 200.80.1.254200.80.1.25514
33200.80.2.0/28200.80.2.1 to 200.80.2.14200.80.2.1514
34200.80.2.16/28200.80.2.17 to 200.80.2.30200.80.2.3114
35200.80.2.32/28200.80.2.33 to 200.80.2.46200.80.2.4714
36200.80.2.48/28200.80.2.49 to 200.80.2.62200.80.2.6314
37200.80.2.64/28200.80.2.65 to 200.80.2.78200.80.2.7914
38200.80.2.80/28200.80.2.81 to 200.80.2.94200.80.2.9514
39200.80.2.96/28200.80.2.97 to 200.80.2.110200.80.2.11114
40200.80.2.112/28200.80.2.113 to 200.80.2.126200.80.2.12714
41200.80.2.128/28200.80.2.129 to 200.80.2.142200.80.2.14314
42200.80.2.144/28200.80.2.145 to 200.80.2.158200.80.2.15914
43200.80.2.160/28200.80.2.161 to 200.80.2.174200.80.2.17514
44200.80.2.176/28200.80.2.177 to 200.80.2.190200.80.2.19114
45200.80.2.192/28200.80.2.193 to 200.80.2.206200.80.2.20714
46200.80.2.208/28200.80.2.209 to 200.80.2.222200.80.2.22314
47200.80.2.224/28200.80.2.225 to 200.80.2.238200.80.2.23914
48200.80.2.240/28200.80.2.241 to 200.80.2.254200.80.2.25514
49200.80.3.0/28200.80.3.1 to 200.80.3.14200.80.3.1514
50200.80.3.16/28200.80.3.17 to 200.80.3.30200.80.3.3114
51200.80.3.32/28200.80.3.33 to 200.80.3.46200.80.3.4714
52200.80.3.48/28200.80.3.49 to 200.80.3.62200.80.3.6314
53200.80.3.64/28200.80.3.65 to 200.80.3.78200.80.3.7914
54200.80.3.80/28200.80.3.81 to 200.80.3.94200.80.3.9514
55200.80.3.96/28200.80.3.97 to 200.80.3.110200.80.3.11114
56200.80.3.112/28200.80.3.113 to 200.80.3.126200.80.3.12714
57200.80.3.128/28200.80.3.129 to 200.80.3.142200.80.3.14314
58200.80.3.144/28200.80.3.145 to 200.80.3.158200.80.3.15914
59200.80.3.160/28200.80.3.161 to 200.80.3.174200.80.3.17514
60200.80.3.176/28200.80.3.177 to 200.80.3.190200.80.3.19114
61200.80.3.192/28200.80.3.193 to 200.80.3.206200.80.3.20714
62200.80.3.208/28200.80.3.209 to 200.80.3.222200.80.3.22314
63200.80.3.224/28200.80.3.225 to 200.80.3.238200.80.3.23914
64200.80.3.240/28200.80.3.241 to 200.80.3.254200.80.3.25514
65200.80.4.0/28200.80.4.1 to 200.80.4.14200.80.4.1514
66200.80.4.16/28200.80.4.17 to 200.80.4.30200.80.4.3114
67200.80.4.32/28200.80.4.33 to 200.80.4.46200.80.4.4714
68200.80.4.48/28200.80.4.49 to 200.80.4.62200.80.4.6314
69200.80.4.64/28200.80.4.65 to 200.80.4.78200.80.4.7914
70200.80.4.80/28200.80.4.81 to 200.80.4.94200.80.4.9514
71200.80.4.96/28200.80.4.97 to 200.80.4.110200.80.4.11114
72200.80.4.112/28200.80.4.113 to 200.80.4.126200.80.4.12714
73200.80.4.128/28200.80.4.129 to 200.80.4.142200.80.4.14314
74200.80.4.144/28200.80.4.145 to 200.80.4.158200.80.4.15914
75200.80.4.160/28200.80.4.161 to 200.80.4.174200.80.4.17514
76200.80.4.176/28200.80.4.177 to 200.80.4.190200.80.4.19114
77200.80.4.192/28200.80.4.193 to 200.80.4.206200.80.4.20714
78200.80.4.208/28200.80.4.209 to 200.80.4.222200.80.4.22314
79200.80.4.224/28200.80.4.225 to 200.80.4.238200.80.4.23914
80200.80.4.240/28200.80.4.241 to 200.80.4.254200.80.4.25514
81200.80.5.0/28200.80.5.1 to 200.80.5.14200.80.5.1514
82200.80.5.16/28200.80.5.17 to 200.80.5.30200.80.5.3114
83200.80.5.32/28200.80.5.33 to 200.80.5.46200.80.5.4714
84200.80.5.48/28200.80.5.49 to 200.80.5.62200.80.5.6314
85200.80.5.64/28200.80.5.65 to 200.80.5.78200.80.5.7914
86200.80.5.80/28200.80.5.81 to 200.80.5.94200.80.5.9514
87200.80.5.96/28200.80.5.97 to 200.80.5.110200.80.5.11114
88200.80.5.112/28200.80.5.113 to 200.80.5.126200.80.5.12714
89200.80.5.128/28200.80.5.129 to 200.80.5.142200.80.5.14314
90200.80.5.144/28200.80.5.145 to 200.80.5.158200.80.5.15914
91200.80.5.160/28200.80.5.161 to 200.80.5.174200.80.5.17514
92200.80.5.176/28200.80.5.177 to 200.80.5.190200.80.5.19114
93200.80.5.192/28200.80.5.193 to 200.80.5.206200.80.5.20714
94200.80.5.208/28200.80.5.209 to 200.80.5.222200.80.5.22314
95200.80.5.224/28200.80.5.225 to 200.80.5.238200.80.5.23914
96200.80.5.240/28200.80.5.241 to 200.80.5.254200.80.5.25514
97200.80.6.0/28200.80.6.1 to 200.80.6.14200.80.6.1514
98200.80.6.16/28200.80.6.17 to 200.80.6.30200.80.6.3114
99200.80.6.32/28200.80.6.33 to 200.80.6.46200.80.6.4714
100200.80.6.48/28200.80.6.49 to 200.80.6.62200.80.6.6314
101200.80.6.64/28200.80.6.65 to 200.80.6.78200.80.6.7914
102200.80.6.80/28200.80.6.81 to 200.80.6.94200.80.6.9514
103200.80.6.96/28200.80.6.97 to 200.80.6.110200.80.6.11114
104200.80.6.112/28200.80.6.113 to 200.80.6.126200.80.6.12714
105200.80.6.128/28200.80.6.129 to 200.80.6.142200.80.6.14314
106200.80.6.144/28200.80.6.145 to 200.80.6.158200.80.6.15914
107200.80.6.160/28200.80.6.161 to 200.80.6.174200.80.6.17514
108200.80.6.176/28200.80.6.177 to 200.80.6.190200.80.6.19114
109200.80.6.192/28200.80.6.193 to 200.80.6.206200.80.6.20714
110200.80.6.208/28200.80.6.209 to 200.80.6.222200.80.6.22314
111200.80.6.224/28200.80.6.225 to 200.80.6.238200.80.6.23914
112200.80.6.240/28200.80.6.241 to 200.80.6.254200.80.6.25514
113200.80.7.0/28200.80.7.1 to 200.80.7.14200.80.7.1514
114200.80.7.16/28200.80.7.17 to 200.80.7.30200.80.7.3114
115200.80.7.32/28200.80.7.33 to 200.80.7.46200.80.7.4714
116200.80.7.48/28200.80.7.49 to 200.80.7.62200.80.7.6314
117200.80.7.64/28200.80.7.65 to 200.80.7.78200.80.7.7914
118200.80.7.80/28200.80.7.81 to 200.80.7.94200.80.7.9514
119200.80.7.96/28200.80.7.97 to 200.80.7.110200.80.7.11114
120200.80.7.112/28200.80.7.113 to 200.80.7.126200.80.7.12714
121200.80.7.128/28200.80.7.129 to 200.80.7.142200.80.7.14314
122200.80.7.144/28200.80.7.145 to 200.80.7.158200.80.7.15914
123200.80.7.160/28200.80.7.161 to 200.80.7.174200.80.7.17514
124200.80.7.176/28200.80.7.177 to 200.80.7.190200.80.7.19114
125200.80.7.192/28200.80.7.193 to 200.80.7.206200.80.7.20714
126200.80.7.208/28200.80.7.209 to 200.80.7.222200.80.7.22314
127200.80.7.224/28200.80.7.225 to 200.80.7.238200.80.7.23914
128200.80.7.240/28200.80.7.241 to 200.80.7.254200.80.7.25514
129200.80.8.0/28200.80.8.1 to 200.80.8.14200.80.8.1514
130200.80.8.16/28200.80.8.17 to 200.80.8.30200.80.8.3114
131200.80.8.32/28200.80.8.33 to 200.80.8.46200.80.8.4714
132200.80.8.48/28200.80.8.49 to 200.80.8.62200.80.8.6314
133200.80.8.64/28200.80.8.65 to 200.80.8.78200.80.8.7914
134200.80.8.80/28200.80.8.81 to 200.80.8.94200.80.8.9514
135200.80.8.96/28200.80.8.97 to 200.80.8.110200.80.8.11114
136200.80.8.112/28200.80.8.113 to 200.80.8.126200.80.8.12714
137200.80.8.128/28200.80.8.129 to 200.80.8.142200.80.8.14314
138200.80.8.144/28200.80.8.145 to 200.80.8.158200.80.8.15914
139200.80.8.160/28200.80.8.161 to 200.80.8.174200.80.8.17514
140200.80.8.176/28200.80.8.177 to 200.80.8.190200.80.8.19114
141200.80.8.192/28200.80.8.193 to 200.80.8.206200.80.8.20714
142200.80.8.208/28200.80.8.209 to 200.80.8.222200.80.8.22314
143200.80.8.224/28200.80.8.225 to 200.80.8.238200.80.8.23914
144200.80.8.240/28200.80.8.241 to 200.80.8.254200.80.8.25514
145200.80.9.0/28200.80.9.1 to 200.80.9.14200.80.9.1514
146200.80.9.16/28200.80.9.17 to 200.80.9.30200.80.9.3114
147200.80.9.32/28200.80.9.33 to 200.80.9.46200.80.9.4714
148200.80.9.48/28200.80.9.49 to 200.80.9.62200.80.9.6314
149200.80.9.64/28200.80.9.65 to 200.80.9.78200.80.9.7914
150200.80.9.80/28200.80.9.81 to 200.80.9.94200.80.9.9514
151200.80.9.96/28200.80.9.97 to 200.80.9.110200.80.9.11114
152200.80.9.112/28200.80.9.113 to 200.80.9.126200.80.9.12714
153200.80.9.128/28200.80.9.129 to 200.80.9.142200.80.9.14314
154200.80.9.144/28200.80.9.145 to 200.80.9.158200.80.9.15914
155200.80.9.160/28200.80.9.161 to 200.80.9.174200.80.9.17514
156200.80.9.176/28200.80.9.177 to 200.80.9.190200.80.9.19114
157200.80.9.192/28200.80.9.193 to 200.80.9.206200.80.9.20714
158200.80.9.208/28200.80.9.209 to 200.80.9.222200.80.9.22314
159200.80.9.224/28200.80.9.225 to 200.80.9.238200.80.9.23914
160200.80.9.240/28200.80.9.241 to 200.80.9.254200.80.9.25514
161200.80.10.0/28200.80.10.1 to 200.80.10.14200.80.10.1514
162200.80.10.16/28200.80.10.17 to 200.80.10.30200.80.10.3114
163200.80.10.32/28200.80.10.33 to 200.80.10.46200.80.10.4714
164200.80.10.48/28200.80.10.49 to 200.80.10.62200.80.10.6314
165200.80.10.64/28200.80.10.65 to 200.80.10.78200.80.10.7914
166200.80.10.80/28200.80.10.81 to 200.80.10.94200.80.10.9514
167200.80.10.96/28200.80.10.97 to 200.80.10.110200.80.10.11114
168200.80.10.112/28200.80.10.113 to 200.80.10.126200.80.10.12714
169200.80.10.128/28200.80.10.129 to 200.80.10.142200.80.10.14314
170200.80.10.144/28200.80.10.145 to 200.80.10.158200.80.10.15914
171200.80.10.160/28200.80.10.161 to 200.80.10.174200.80.10.17514
172200.80.10.176/28200.80.10.177 to 200.80.10.190200.80.10.19114
173200.80.10.192/28200.80.10.193 to 200.80.10.206200.80.10.20714
174200.80.10.208/28200.80.10.209 to 200.80.10.222200.80.10.22314
175200.80.10.224/28200.80.10.225 to 200.80.10.238200.80.10.23914
176200.80.10.240/28200.80.10.241 to 200.80.10.254200.80.10.25514
177200.80.11.0/28200.80.11.1 to 200.80.11.14200.80.11.1514
178200.80.11.16/28200.80.11.17 to 200.80.11.30200.80.11.3114
179200.80.11.32/28200.80.11.33 to 200.80.11.46200.80.11.4714
180200.80.11.48/28200.80.11.49 to 200.80.11.62200.80.11.6314
181200.80.11.64/28200.80.11.65 to 200.80.11.78200.80.11.7914
182200.80.11.80/28200.80.11.81 to 200.80.11.94200.80.11.9514
183200.80.11.96/28200.80.11.97 to 200.80.11.110200.80.11.11114
184200.80.11.112/28200.80.11.113 to 200.80.11.126200.80.11.12714
185200.80.11.128/28200.80.11.129 to 200.80.11.142200.80.11.14314
186200.80.11.144/28200.80.11.145 to 200.80.11.158200.80.11.15914
187200.80.11.160/28200.80.11.161 to 200.80.11.174200.80.11.17514
188200.80.11.176/28200.80.11.177 to 200.80.11.190200.80.11.19114
189200.80.11.192/28200.80.11.193 to 200.80.11.206200.80.11.20714
190200.80.11.208/28200.80.11.209 to 200.80.11.222200.80.11.22314
191200.80.11.224/28200.80.11.225 to 200.80.11.238200.80.11.23914
192200.80.11.240/28200.80.11.241 to 200.80.11.254200.80.11.25514
193200.80.12.0/28200.80.12.1 to 200.80.12.14200.80.12.1514
194200.80.12.16/28200.80.12.17 to 200.80.12.30200.80.12.3114
195200.80.12.32/28200.80.12.33 to 200.80.12.46200.80.12.4714
196200.80.12.48/28200.80.12.49 to 200.80.12.62200.80.12.6314
197200.80.12.64/28200.80.12.65 to 200.80.12.78200.80.12.7914
198200.80.12.80/28200.80.12.81 to 200.80.12.94200.80.12.9514
199200.80.12.96/28200.80.12.97 to 200.80.12.110200.80.12.11114
200200.80.12.112/28200.80.12.113 to 200.80.12.126200.80.12.12714
201200.80.12.128/28200.80.12.129 to 200.80.12.142200.80.12.14314
202200.80.12.144/28200.80.12.145 to 200.80.12.158200.80.12.15914
203200.80.12.160/28200.80.12.161 to 200.80.12.174200.80.12.17514
204200.80.12.176/28200.80.12.177 to 200.80.12.190200.80.12.19114
205200.80.12.192/28200.80.12.193 to 200.80.12.206200.80.12.20714
206200.80.12.208/28200.80.12.209 to 200.80.12.222200.80.12.22314
207200.80.12.224/28200.80.12.225 to 200.80.12.238200.80.12.23914
208200.80.12.240/28200.80.12.241 to 200.80.12.254200.80.12.25514
209200.80.13.0/28200.80.13.1 to 200.80.13.14200.80.13.1514
210200.80.13.16/28200.80.13.17 to 200.80.13.30200.80.13.3114
211200.80.13.32/28200.80.13.33 to 200.80.13.46200.80.13.4714
212200.80.13.48/28200.80.13.49 to 200.80.13.62200.80.13.6314
213200.80.13.64/28200.80.13.65 to 200.80.13.78200.80.13.7914
214200.80.13.80/28200.80.13.81 to 200.80.13.94200.80.13.9514
215200.80.13.96/28200.80.13.97 to 200.80.13.110200.80.13.11114
216200.80.13.112/28200.80.13.113 to 200.80.13.126200.80.13.12714
217200.80.13.128/28200.80.13.129 to 200.80.13.142200.80.13.14314
218200.80.13.144/28200.80.13.145 to 200.80.13.158200.80.13.15914
219200.80.13.160/28200.80.13.161 to 200.80.13.174200.80.13.17514
220200.80.13.176/28200.80.13.177 to 200.80.13.190200.80.13.19114
221200.80.13.192/28200.80.13.193 to 200.80.13.206200.80.13.20714
222200.80.13.208/28200.80.13.209 to 200.80.13.222200.80.13.22314
223200.80.13.224/28200.80.13.225 to 200.80.13.238200.80.13.23914
224200.80.13.240/28200.80.13.241 to 200.80.13.254200.80.13.25514
225200.80.14.0/28200.80.14.1 to 200.80.14.14200.80.14.1514
226200.80.14.16/28200.80.14.17 to 200.80.14.30200.80.14.3114
227200.80.14.32/28200.80.14.33 to 200.80.14.46200.80.14.4714
228200.80.14.48/28200.80.14.49 to 200.80.14.62200.80.14.6314
229200.80.14.64/28200.80.14.65 to 200.80.14.78200.80.14.7914
230200.80.14.80/28200.80.14.81 to 200.80.14.94200.80.14.9514
231200.80.14.96/28200.80.14.97 to 200.80.14.110200.80.14.11114
232200.80.14.112/28200.80.14.113 to 200.80.14.126200.80.14.12714
233200.80.14.128/28200.80.14.129 to 200.80.14.142200.80.14.14314
234200.80.14.144/28200.80.14.145 to 200.80.14.158200.80.14.15914
235200.80.14.160/28200.80.14.161 to 200.80.14.174200.80.14.17514
236200.80.14.176/28200.80.14.177 to 200.80.14.190200.80.14.19114
237200.80.14.192/28200.80.14.193 to 200.80.14.206200.80.14.20714
238200.80.14.208/28200.80.14.209 to 200.80.14.222200.80.14.22314
239200.80.14.224/28200.80.14.225 to 200.80.14.238200.80.14.23914
240200.80.14.240/28200.80.14.241 to 200.80.14.254200.80.14.25514
241200.80.15.0/28200.80.15.1 to 200.80.15.14200.80.15.1514
242200.80.15.16/28200.80.15.17 to 200.80.15.30200.80.15.3114
243200.80.15.32/28200.80.15.33 to 200.80.15.46200.80.15.4714
244200.80.15.48/28200.80.15.49 to 200.80.15.62200.80.15.6314
245200.80.15.64/28200.80.15.65 to 200.80.15.78200.80.15.7914
246200.80.15.80/28200.80.15.81 to 200.80.15.94200.80.15.9514
247200.80.15.96/28200.80.15.97 to 200.80.15.110200.80.15.11114
248200.80.15.112/28200.80.15.113 to 200.80.15.126200.80.15.12714
249200.80.15.128/28200.80.15.129 to 200.80.15.142200.80.15.14314
250200.80.15.144/28200.80.15.145 to 200.80.15.158200.80.15.15914
251200.80.15.160/28200.80.15.161 to 200.80.15.174200.80.15.17514
252200.80.15.176/28200.80.15.177 to 200.80.15.190200.80.15.19114
253200.80.15.192/28200.80.15.193 to 200.80.15.206200.80.15.20714
254200.80.15.208/28200.80.15.209 to 200.80.15.222200.80.15.22314
255200.80.15.224/28200.80.15.225 to 200.80.15.238200.80.15.23914
256200.80.15.240/28200.80.15.241 to 200.80.15.254200.80.15.25514

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.